ALPHA DECAY HALF LIVES OF 242PU AND 244PU

The partial alpha decay half lives of 242Pu and 244Pu have been determined by a relative specific activity technique using 239Pu as the reference. The measured alpha decay half lives are (3·869±0·016) × 105 yr and (8·28±0·10) × 107 yr respectively. Alpha particle energies (and intensities) to the ground state and to the first excited state in 240U from the decay of 244Pu have been measured to be 4·587±0·001 MeV (80·6 per cent) and 4·544±0·001 MeV (19·4 per cent) respectively. The alpha decay Q-value for 244Pu has been determined to be 4·701±0·001 MeV. © 1969.